A lineage of diploid platelet-forming cells precedes polyploid megakaryocyte formation in the mouse embryo

Blood. 2014 Oct 23;124(17):2725-9. doi: 10.1182/blood-2014-02-559468. Epub 2014 Jul 25.


In this study, we test the assumption that the hematopoietic progenitor/colony-forming cells of the embryonic yolk sac (YS), which are endowed with megakaryocytic potential, differentiate into the first platelet-forming cells in vivo. We demonstrate that from embryonic day (E) 8.5 all megakaryocyte (MK) colony-forming cells belong to the conventional hematopoietic progenitor cell (HPC) compartment. Although these cells are indeed capable of generating polyploid MKs, they are not the source of the first platelet-forming cells. We show that proplatelet formation first occurs in a unique and previously unrecognized lineage of diploid platelet-forming cells, which develop within the YS in parallel to HPCs but can be specified in the E8.5 Runx1-null embryo despite the absence of the progenitor cell lineage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Lineage / genetics*
  • Core Binding Factor Alpha 2 Subunit / genetics
  • Core Binding Factor Alpha 2 Subunit / metabolism
  • Diploidy*
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / embryology
  • Embryo, Mammalian / metabolism*
  • Gene Expression Regulation, Developmental
  • Megakaryocyte Progenitor Cells / cytology
  • Megakaryocyte Progenitor Cells / metabolism*
  • Megakaryocytes / cytology
  • Megakaryocytes / metabolism*
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Microscopy, Confocal
  • Oligonucleotide Array Sequence Analysis
  • Polyploidy*
  • Time Factors
  • Transcriptome
  • Yolk Sac / cytology
  • Yolk Sac / embryology
  • Yolk Sac / metabolism


  • Core Binding Factor Alpha 2 Subunit
  • Runx1 protein, mouse